ok i'm contemplating getting a nikon dslr depending on specs etc of the d400 when it appears to replace my pentax k-7

so was looking at the lenses available and am struggling with what i would have thought to be the easiest one to chose

i would want a fast normal zoom in and around the 18-50mm range constant f2.8 and vibration reduction - but the only lens i can see lacks the VR

that would leave me getting a sigma lens - which i admit i use a sigma on my pentax but only because there have been some quality control issues with the pentax DA*16-50mm's autofocus motor

sure its maybe not critical on most things at these focal lengths but in low light condidtions it can help get the shot

so does such a lens exist and just not stocked where i'm searching in the right place or does nikon not do such a lens? ironically i wanted to switch to nikon for better telephoto lens choice but seems if i'm gonna struggle with the other end of the spectrum now

You aren't going to find a 2.8 stabilized under a 70-200, the closet is the 16-35 f4 vr
and can you elaborate what you are looking for in this lens/ body combo. The "d400" is still a rumor, and i bet the d7000 (d90 replacement) will be out before a d400 so dont hold your breath.